The manufactured forms and presentation forms of washing and cleaning agents are constantly subject to new modifications. In this regard, a main focus for some time has been on the convenient metering of washing and cleaning agents and the simplification of the process stages required for carrying out a washing or cleaning process.
In this context, devices for the multi-dosing of washing and cleaning agents have recently become a focus of attention for the product developer. For these devices one can differentiate between, on the one hand metering containers that are integrated into the automatic dishwasher or washing machine, and on the other hand devices that are independent from the automatic dishwasher or washing machine. In the course of a plurality of sequential cleaning stages portions of detergent or cleaning agent are automatically or semi-automatically metered into the interior of the cleaning machine by these devices that contain the multiple doses of cleaning agent required for carrying out a cleaning process. The consumer no longer needs to dose the cleaning agent prior to each individual cleaning operation. Examples of such devices are described in the European patent application EP 1 759 624 A2 (Reckitt Benckiser) or in the German patent application DE 10 2005 062 479 A1 (BSH Bosch and Siemens Hausgeräte GmbH).
Independently of the exact design of the metering device placed in the interior of the automatic dishwashers or washing machines, the washing or cleaning agents that are contained in these devices for multiple metering are exposed for a long period of time, in particular to varying temperatures, these temperatures being approximately equivalent to the temperatures of the water used for carrying out the washing or cleaning process. These temperatures can be up to 95° C., wherein in automatic dishwashing usually temperatures between 50 and 75° C. are attained. In the course of multiple laundry or cleaning processes a washing or cleaning agent contained in a device intended for multiple dosing will therefore be repeatedly heated to temperatures significantly above those that are usual for transportation and storage; temperature-sensitive, active substances will be particularly affected. The group of these temperature-sensitive active washing and cleaning substances includes primarily the active washing and cleaning enzymes.
The use of enzymes to improve the laundry and cleaning power of washing and cleaning agents has been established in the prior art for some decades. In particular, hydrolytic enzymes such as proteases, amylases or lipases, due to their direct cleaning action, are a component of numerous cleaning agents for fabrics or table ware.
Proteases, especially serine proteases, to which the subtilases are also associated according to the invention, serve to degrade protein-containing stains on the product being cleaned. Subtilases, due to their favorable enzymatic properties, such as stability or pH optimum, have a preeminent position among the washing and cleaning proteases. From the amylase enzyme class, the α-amylases are prevalent; α-amylases (E.C. 3.2.1.1) hydrolyze internal α-1,4-glycosidic bonds of starch and starch-like polymers.
In the washing and cleaning agents, the cleaning action of the incorporated enzyme which is decisive for the consumer, is also determined, in addition to the enzyme structure, to a significant degree by the type of packaging of the enzyme and its stabilization against environmental influences.
Active washing and cleaning enzymes are made up both in solid as well as in liquid form. The group of solid enzyme preparations includes in particular the enzyme granulates that consist of a plurality of ingredients and which are preferably incorporated into solid washing and cleaning agents. On the other hand, liquid or gel type washing and cleaning agents frequently comprise liquid enzyme preparations, these being much less protected against external influences than the enzyme granulates.
A series of different protective measures have been proposed in order to increase the stability of these types of enzyme-containing liquid washing or cleaning agents. Thus, for example, the German patent application DE 2 038 103 (Henkel) teaches the stabilization of enzyme-containing dishwashing agents by saccharides, whereas propylene glycol is disclosed in the European patent EP 646 170 B1 (Procter & Gamble) for stabilizing enzymes in liquid cleaning agents.
The hitherto found methods described in the prior art for stabilizing enzymes take into account only to a limited extent the problematic nature of repeated exposure to high temperatures, as for example occur in the above described devices for multiple dosing of washing or cleaning agents. The previously known methods are only suitable to a limited extent for avoiding a loss of activity or for avoiding segregation of the enzyme in liquid cleaning agents.
Accordingly, it is desirable to stabilize an active washing or cleaning enzyme preparation against phase separation/loss of activity during multiple variations in temperature, in particular in a temperature range of 10 to 75° C. It is further desirable to enable enzyme preparations to be storable without significant loss of activity in a storage device located in the interior of the automatic dishwasher or washing machine.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.